[PATCH] add documentation about backend naming for VMOD authors

[Dridi Boukelmoune]

>>Sounds good, and for static backends defined in plain native vcl,
>>backend.display_name == vcl.loaded_name + "." + director.vcl_name
>
> *All* backend names has the from "$VCL.something"

What I meant is that dynamic backends should start with $VCL.something
(the whole suffix discussion), while static backends are strictly
$VCL.something. I wasn't disagreeing but adding to the summary.

>>They are currently always in the CLI/VSM, and this is controlled by
>>the VCL temperature changes. But I think a struct director with a
>>struct backend should always show up in the CLI/VSM.
>
> It probably should *almost* always show up, but there are valid
> schenarios where a struct backend is good for a single request
> and I can see why you wouldn't want to clutter CLI/VSM with that.

Just to get rid of ambiguity here, is it your vmod-cgi example?